chore(ci): add yamllint

.woodpecker.yaml

@@ -0,0 +1,13 @@
+---
+labels:
+  backend: kubernetes
+steps:
+  - name: linting
+    image: cytopia/yamllint:latest
+    commands:
+      - yamllint -f colored -s .
+when:
+  - event:
+      - push
+      - manual
+      - pull_request

.yamllint

@@ -0,0 +1,12 @@
+---
+yaml-files:
+  - '*.yaml'
+  - '*.yml'
+  - '.yamllint'
+
+extends: default
+
+rules:
+  line-length: disable
+  indentation:
+    indent-sequences: consistent